1. Field of the Invention
The present invention relates to a method of producing a laminate.
2. Description of the Related Art
A polarizing film is placed on each of both sides of a liquid crystal cell of a liquid crystal display apparatus as a typical image display apparatus, the placement being attributable to an image-forming system of the apparatus. As a method of producing the polarizing film, for example, there has been proposed a method involving stretching a laminate including a resin substrate and a polyvinyl alcohol (PVA)-based resin layer, and immersing the stretched laminate in a dyeing liquid to provide a polarizing film (for example, Japanese Patent Application Laid-open No. 2001-343521). Such method has been attracting attention as a potential approach to contributing to thinning of the liquid crystal display apparatus in recent years because the method provides a polarizing film having a small thickness. The PVA-based resin layer is formed by applying and drying an application liquid containing a PVA-based resin. It is desirable to remove air bubbles from the application liquid because presence of the air bubbles in the application liquid causes a streak- or dot-like external appearance defect in the PVA-based resin layer to be formed. As a technology for removing the air bubbles in the application liquid, there has been known a technology involving passing a film-forming raw material using a PVA-based polymer as a constituent component through a filter in production of a PVA-based polymer film (for example, Japanese Patent Application Laid-open No. 2002-144419). However, in the related art, it is difficult to remove air bubbles in the filter when the film-forming raw material (i.e., the application liquid) is passed through the filter (substantially when the filter is filled with the application liquid in association with the passage). As a result, it is difficult to remove the air bubbles from the application liquid. Even if the air bubbles can be removed, the removal requires much time, which results in insufficient productivity.